I hear the cycle breaking all the way over in WI. Doesn't it feel good just to love...just plain love. We all have our needs, but when you just focus on loving because you want to, things DO start changing. Talking about your feelings and fears is at the heart of sharing love.
Comments on her letter: (you guys found a good communication tool here, keep using it if it works, especially for the hard stuff to say and hard stuff to express)
She needed to hear about your love for her. I'm glad you did that. She's right, it's easy to forget it when dealing with extremely hard events/reoccurances in a marriage.
She explained her fear even though it may be tough for you to hear. You can't work out anything that you don't know about. I know that fear she has. I felt that I didn't have ample time "finding myself" either, and I even went to college. I guess what I found out is that I think most everyone get to this place after some years in a marriage. People change. She is realizing things about herself now that she hadn't before. I believe even if she had gone to college, she would still have gotten to this place. She is a different person now than she was back then. She is older, she has learned things, she sees things with more mature eyes, the kids are getting older and all the focus doesn't have to be on them, she is having time to "see" herself, and she has had an affair. I think this is what people mean when they say "we grew apart". You can either confide in your H (like she is doing), share your fears, and grow together, or you can go off on your own in search of answers. I've wondered before if I would have "picked" my husband now if I were single. We are constantly changing and growing as people, if we tried to find someone that met those specific changing needs every time, we would have to find new partners often.
The counselor can help her sort through these things. It IS a pro marriage counselor, right? I'm no counselor, but I could guess that you could get to the heart of what she feels is missing, and work together on fixing it. I don't think she will find she needs to leave the one she loves to be content and happy. I went through a long spell of wondering if I will be happy, and what I found is it is not who I am with that makes me happy...for me, it is the little things now. When I get that feeling like she is still having, I plan something with my H that will satisfy it (it is usually "excitement" that is missing and that causes that feeling). Again, the counselor should help her.
As for what to tell the kids. That's fine what she says. I don't like the way she is leaving the back door open to leave, but I guess if she DOES end up giving up it would be best for the kids to know that is a possibility. Be prepared with answers to questions your kids may have. Maybe practice with your wife thinking of each child and what they may say. There's nothing wrong with telling them how YOU feel. Just because she has a way SHE wants to put it, doesn't mean that you may not have a slightly different feeling about it. Talk to her first about it, though. If my H said what she did, I would also want to add myself that I have learned that marriage is a lifelong commitment.....when I took the vows for better or for worse, in good times and in bad, I meant it. I put my life in God's hands. That's me, but I'm closer to my faith than ever these days.
Renewal of vows. She still thinks you may not work out so she won't do them yet. You don't want to do them if she feels that way. Better wait. From what I read, she is saying she is committed to WORKING on the marriage, not committed to the marriage.
Ok, you guys are off to a good start. You know what is going on in her head, she knows your fears and some of your needs, and you are both working on them. Keep this going, even when it gets to a bad spot ('cause it will), you keep loving her. Having a good marriage is hard work. Don't forget to watch that movie.
By they way: You said, "In any event, I'm going to try to initiate tonite and/or tomorrow, and am going to make sure to do it forcefully and playfully, and if I get rejected, it's going to be more of a "hey, your loss hotcheeks!" thing." - PERFECT! Now you got it!